Electrical controlling device.



C. F. LORENZ.

ELECTRICAL CONTROLLING DEVICE.

APPLICATION FILED 8.12.1917.

Patented Mar. 18, 1919.

UNITED STATES PATENT OFFICE.

CHARLES IF. LORENZ, OF CLEVELAND, OHIO, ASSIGNOR TO GENERAL ELECTRIC COMPANY, ACORPORATION OF NEW YORK.

ELECTRICAL CONTROLLING DEVICE.

To all whom it may concern:

Be it known that I, CHARLES F. LORENZ, a citizen of the United States, residing at Cleveland, county of Cuyahoga, State of Ohio, have invented new and useful Improvements in Electrical Controlling Devices, of which the following is a specification.

My invention relates to the control of electrical devices of various types but is particularly adapted to the control of electric illuminating and heating devices. 7

My invention is especially adapted to the control of electrical devices embodying conductors of high temperature coeflicien-ts, as for instance, metallic filament lamps, and in the present application is applied to the control of tungsten filament lamps which, as known, have a-large positive temperature coefiicient. The object of my invention is a simple arrangement whereby the illumination intensity of a metallic filament may be simply and easily controlled either at the lamp socket'or at a point remote therefrom, without the necessity of the usual additional circuits and switches accompanying prior systems of regulation. In accordance With my invention I take advantage of the high positive temperature coefficient of the filament to either run the lamp at a high or at a low intensity and in carrying out my invention I insert in series with the filament a miniature electromagnet which is designed with suflicient power to operateits armature when the filament is cold, but when the filament is heated up, as by momentarily passing a current therethrough, the current flowing under these conditionsis insufficient to operate the armature and the armature remains in the open position during the con- ,tinuance ofthe flowing of the current in the circuit. The armature of the electromagnet is adapted to short circuit a resistor in series with the filament and this resistor may be an auxiliary filament in the incandescent lamp bulb which is designed to glow when the armature. is in the open tion} .In accordance with this modification-the lectromagnet 1s inclosed 1n the base Specification of Letters Patent.

Patented Mar. 18, 1919.

Application filed April 12, 1917. Serial No. 161,431.

ing sufficient to operate the armature and short circuit the resistor. To operate dim or at low intensity the switch is closed momentarily, then off, andthen on again, these three operations rapidly following each other. In the latter case the first rush of current heats the lamp filament and causes a: substantial rise in its resistance and when the circuit is momentarily opened again the armature ofthe magnet which v has closed during the first rush of current falls awa and when the circuit is closed the seconc time the current under the high temperature conditions of the filament is insufficient to operate the magnet and the resistor remains in circuit and causes the lamp to operate dim. This arrangement has a number of advantages, among which may be mentioned the simplicity of the control whereby no additional Wiring is necessary and the usual wall switch maybe used to control the lamp.- In fact any switch anywhere in the circuit may be used with equal facility for controlling the lamp.

For other advantages of my invention and for a better understanding thereof, reference may be had to the drawings accompanying this specification, Figure l of which is a side view of an incandescent lamp embodying my invention, Fig; 2 is a sectional view thereof, Fig. 3 is a modification of my in-.

justable stop 5, this armature 4 being adapted to be pulled over against the core of the magnet against the tension of the leaf spring support of the armature. This controlling electromagnet rests on an insulating partition 6 and the whole compartment may be sealed asshown and filled with some insulation liquid, as a suitable oil, the oil in addition to its insulating qualities serving to damp out vibrations of the armature 4 when the lamp is energized by alternating currents. A conventional switch 7 is illustrated which may be either the switch in the lamp socket or may be a remote switch located on the wall or at some other convenient point of control. In Figs. 1 and 2 a resistor 8 is connected in the circuit and consists of an auxiliary filament and is adapted to operate dim when the main filament 9 is not illuminated. The magnet coil 3 is at all times, as illustrated, connected in C11- cuit while the resistor 8 is adapted to be short-circuited by the engagement of the armature 4 with the core of the electromagnet.

The operation is as follows: When the switch 7 is closed the current from the positive side of the line throws through the lamp base shell to the leading in wire 10, from the leading in wire 10 to and through the main filament 9 to leading in wire 11. From leadin in wire 11 the current passes down again 1nto the auxiliary filament 8 through one of its leading in wires and back again through the other leading in wire through conductor 12 to the core of the electromagnet and from this core the circuit continues through the coil 3 to the negative side of the line. The filament 9 being cold and, therefore, at a low resistance, a rush of current occurs which is sutficient to operate .the armature 4 of the magnet and the closing of this armature short circuits the auxiliary filament 8 and the lamp continues to operate bright until the switch 7 is opened. It is understood that once the armatuie 4 is closed the current flowing through the electromagnet is sufiicient: to retain the same in the closed position, even under the low current conditions. To operate the lamp dim the switch 7 has only to be opened momentarily and long enough for the armature 4 to be withdrawn from engagement with the core, then quickly closed again before the filament 9 has an opportunity to cool off. On the second closing of the switch the current is insufiicient to re-close the armature 4 and accordingly the auxiliary filament 8 remains in the circuit and in this particular case is designed to furnish the illumination of low intensity, the filament 9 hardly glowing under the low current conditions.

In Fig. 3 is illustrated a modification of my invention which is applied to a connector or adapter which may be inserted in the circuit to the lamp at any convenient point. Inthe particular arrangement shown the connector embodies a combined screw base and shell socket which may be inserted in the usual fixtures and receive a lamp of standard construction therein. This embodies an electromagnet coil 3. and its armature 4' and the resistor 8. This resistor 8 is conventionally illustrated and may assume any suitable form for inclosurein the adapter and itself may be of a positive temperature coeflicient like the filament with which it is inserted in series. The operation of this modification is :similar to the operation of the modification illustrated in Figs. 1 and 2,

except that in this case the resistor 8 is not adapted to furnish any of the illumination and the main filament of the lamp operates both bright and low dependent upon whether the resistor is in circuit or short circuited by the electromagnet.

What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. In a control system, an electrical device to be controlled embodying a conductor of a high positive temperature coefiicient, a resistor in series with the conductor and an electromagnet adapted to short circuit said resistor when the circuit is first closed and to retain the short circuit during the contions.

3. In a control system a metallic filament incandescent lamp, a resistor in series with the filament and an electromagnet adapted to short circuit said resistor when the circuit is first closed and retain the short circuit during the continued burning of the lamp, the power of said magnet being insufiicient to short circuit the resistor under the influence of the low current under the high temperature condition of the filament.

4. In a control system a tungsten filament incandescent lamp, a resistor in series with the lamp, and an electromagnet in series therewith adapted to short circuit the resistor when the circuit is first closed, the power of said electromagnet being sufficient to retain the short circuitduring the continued burning of the lamp, but insufficient to operate the short circuit under the low current and high temperature conditions ofp the filament.

i 5. An adapter for insertion in the circuit shortci'rcuit the resistor under the low curof a metallic filament lamp embodying a rerent and high temperature conditions of the sistor and an electromagnet adapted to short filament. 10 circuit said resistor when the circuit is first In Witness whereof, I have hereunto set 5 closed and retain the short circuit during my hand this 10th day of April, 1917.

the continued closure of the circuit, the p power of said magnet being insufiicient to CHARLES F. LORENZ. 

